The idea of 9 to 5 is a thing of the past at some companies in Volusia County that schedule flexible hours to help employees fit work into their hectic lives.

At Eltec Instruments Inc., flexible working hours are a necessity for much of its assembly staff, most of whom are women, said company vice president Charlene Hartman. The company has traditionally hired women for its delicate assembly process in the manufacture of infrared detection systems.

When employees take time off during the week, it's usually to take a child to the doctor, pick up a baby sitter or some other family-oriented task. ''It typically is for the children,'' Hartman said.

Eltec employees work a longer day during the week and can take Friday afternoon off. Hours missed can be made up on Friday to complete the 37-hour work week, said personnel director Debra Reno.

At Tanning Research Laboratories Inc. in Ormond Beach the tradition of Friday afternoons off began a different way. A few summers ago, employees worked a longer week to get Friday afternoons off for extra relaxation.

They liked it so much the practice lasted through the winter and became part of the permanent schedule for many workers at the company, which produces Hawaiian Tropic sun care and cosmetic products, said Bill Darby, vice president of marketing.

''It made for a better weekend and a happier employee,'' Darby said. Many of the 250 company employees use the afternoon off to work on their suntans, which are important for Hawaiian Tropic's image, he said.

Lynn Christman, a marketing assistant at Tanning Research Laboratories, said she was delighted to find the company had Friday afternoons off when she came to work there a year and a half ago. ''It definitely attracted me to it,'' said Christman.

About 15 percent of Volusia County's companies make flexible hours available for their employees, according to a recent survey of 73 companies conducted by the Volusia Manufacturing Association. The program can be successful unless companies depend on assembly lines which require employees to work simultaneously, said association executive director Lou Fifer.

''This works at the outfits that are high tech and high quality because the order can be delivered whenever,'' Fifer said. But the hours have to conform to a set pattern because supervisors can't be on duty all the time, he said.

''If you agree to a certain plan you have to stick to it,'' Fifer said. In the fast food industry, companies commonly use flexible hours to attract workers. The fast food chains in Volusia, where unemployment is low and service workers can be hard to find, use flexible hours to lure employees who otherwise would not be able to work, such as students and senior citizens.

At Eddy Corp., which owns 11 McDonald's restaurants in Volusia, the company works with senior citizens to make sure they can hold down a part-time job and still receive full social security benefits, said company public relations coordinator Dodie Behringer. People work a minimum of two hours a day for Eddy Corp. restaurants, Behringer said.

''They can name their own times and their own days,'' she said. Eddy Corp. has 24 stores in Volusia, Lake, Flagler and Orange counties.

Jeanette Bishop, 66, a retired factory employee who has worked at the Holly Hill McDonald's for a year and a half, said she started work because she was bored with retirement. Working 25 hours a week is enough to keep her occupied and give her extra money, she said.

To attract students, Wendcoast Management Inc. bends hours around a high school schedule. ''If they're in the band and in the school play, we work around it,'' said vice president of marketing Cassandra Flinn. Wendcoast manages 56 Wendy's restaurants in Central and Northeast Florida, including 11 in Volusia.